Folding ladder



S e'pt. 28,1965 L. GRAY FOLDING LADDER 2 Sheets-Sheet 1 Filed 001;. 15,1963 L. GRAY FOLDING LADDER I Sept 28, 1965 2 Sheets-Sheet 2 Filed Oct.15, 1963 INVENTOR GRAY ATTORNEY United States Patent 3,208,553 FOLDINGLADDER Lanier Gray, 214 N. Pitt St., Alexandria, Va. Filed Oct. 15,1963, Ser. No. 316,246 11 Claims. (Cl. 182-24) The present inventionrelates to an improved ladder, and more particularly to a light weight,tubular ladder which is foldable to occupy a minimum of space forstorage and unfoldable to provide either an extension or step ladder,the construction being such that the ladder is also divisible intoindividual step ladders usable as supports for a platform.

It is an important object of the invention to provide a light weight,sectionalized, step ladder foldable into a compact package for storageand wherein the sections are hinged together and when folded liecontiguously one over another.

Another object of the invention is to provide a ladder, of the abovedescribed characteristics, which may be quickly and readily unfolded andthe sections aligned to form an extension ladder.

A further object of the invention is to provide an improved ladder, ofthe above described characteristics, which may be unfolded to form astep ladder in which adjacent sections are locked together at an acuteangle.

It is still another object of the invention to provide a ladder, of theabove described characteristics, wherein is additionally provided aseparable extension section which may be readily assembled, to theremaining sections, or as readily disassembled therefrom.

Yet another object of the invention is to provide an improved ladder, ofthe above described characteristics, wherein the individual sectionscomprise stiles having tubular cross sections formed of a lightweightmaterial so as to provide sturdiness as well as lightness, the reducedweight permitting ready folding and unfolding manipulations by oneperson.

A still further object of the invention is to provide an improvedladder, having the above described characteristics, wherein tubular lockmeans is provided within at least some of the sections, said means beingeasily slideable longitudinally into telescopic engagement with anadjacent section for locking said sections together, the tubularconstruction of the lock means being such as to provide a rigid andsturdy connection between sections when unfolded and locked together.

Yet a further object of the invention is to provide an improved ladder,having the above described characteristics, wherein hinges are providedbetween adjacent sections, each hinge having resilient, releasable latchmeans for locking adjacent sections together at a preselected angle.

Still another object of the invention is to provide an improved ladder,having the above described characteristics, which is of simpleconstruction, easy and economical to fabricate, and easy to fold andunfold.

The novel features that are considered characteristic of the inventionare set forth with particularity in the appended claims. The inventionitself, however, both as to its organization and its method ofoperation, together with additional objects and advantages thereof, willbest be understood from the following description of specificembodiments when read in connection with the accompanying drawings,wherein like reference characters indicate like parts throughout theseveral figures and in which:

FIG. 1 is a side elevation of a ladder according to the invention whichhas been unfolded to form a step ladder;

FIG. 2 is an end elevation of the step ladder of FIG. 1;

FIG. 3 is a side elevation of the same ladder unfolded to form anextension ladder;

FIG. 4 is an enlarged, perspective view of portions of two adjacentladder sections, partially broken away to reveal inner details, andindicating by arrow the mode of unfolding said sections;

FIG. 5 is a perspective view similar to FIG. 4 but showing the sectionsturned into alignment and locked together;

FIG. 6 is a fragmentary, enlarged, vertical sectional view of the upperend of the step ladder of FIG. 1, with the upper support exploded to aposition ready for assembly with the unfolded and angled, uppersections;

FIG. 7 is an enlarged section taken on line 7- 7 of FIG. 1 and lookingin the direction of the arrows;

FIG. 8 is an elevation showing the ladder folded for storage;

FIG. 9 is an elevation showing the ladder separated into two short stepladders for support of a platform;

FIG. 10 is a fragmentary, enlarged, sectional elevation of portions ofthe ladder sections as shown in FIG. 9, illustrating the bracing pivotarms which hold the sections at an angle to each other, and

FIG. 11 is a side elevation of an extension for the ladder of FIG. 3assembled to a fragment of the upper section.

Referring now more particularly to the drawings, the foldable, combinedextension and step ladder may be composed of two or more sections andpreferably comprises at least four separate sections 10, 12, 14 and 16,respectively. These four sections, as shown in FIGS. 1 and 2 havelaterally spaced side bars, or stiles 18, and vertically spacedtransverse connecting rungs 20. The stiles 18 are preferably formed ashollow tubes of rectangular cross section and the rungs 20 ascylindrical tubes welded, or otherwise secured at their ends, to thestiles, however, these elements may obviously have other cross-sectionalshapes. Both the upper and lower ends of all stiles 18 are preferablyrounded as shown at 22. The completed sections and their components aredesirably identical in dimensions, having the same overall widths andlengths. For lightness, the described elements may be formed of alightweight metal such as magnesium, or aluminum. If desired they may beformed of a sturdy plastic or other suitable material.

Connecting adjacent ones of sections 10, 12, 14 and 16, preferably atboth side faces of each stile, are the hinges generally indicated by thereference numeral 24. Each hinge, as best shown in FIGS. 4, 5 and 7,comprises a metal strap 26 having openings at its opposite ends 28 and30 in which are respectively received the pivot studs 32 and 34. Pivot32 may be formed as a rivet having heads on each end, one of which issoldered, or welded, to the associated stile and countersunk so that itis flush with the inner surface thereof. The outer head overlies thewall of opening 28 and retains the strap 26 pivotally secured to thestile. The pivot stud 34 desirably is headed only at its inner end, andcountersunk in and secured to its associated stile. The outer head ispreferably omitted so that strap 26 may be removed from stud 34 bypulling the end of the strap outwardly. An opening is formed throughpivot stud 34 to receive a cotter pin 37, or other suitable fasteningelement as shown in FIG. 7. The pivot studs 32 and 34 are positioned onboth outer and inner faces of opposed side walls of adjacent stiles andat the centers of their curved ends 22 so that the hinge means 24permits the adjacent sections to turn through an angle of 360 with thecurved edges 22 in rolling contact. Such turning enables the adjacentsections of the ladder to be folded so as to lie contiguously, one overthe other, as shown in FIG. 8, or to be unfolded in the manner indicatedby arrow A of FIG. 4 so that the adjacent sections form an acute angleas illustrated in FIG. 1, or to be unfolded into alignment asillustrated in FIGS. 3 and 5.

Referring again to FIGS. 4 and 7 at least the outer hinges 24 areprovided with a resilient latch formed by a spring metal strap 36,secured near one end by rivet 38 to the strap 26, and having its otherend 40 outwardly bent and curled. A pin 42 is fixed to the strap nearend 40 and passes inwardly through aligned openings 44 and 46 in thestrap 26 and stile 18 respectively. Opening 46, as best shown in FIG. 4is positioned in the stile so that when the adjacent sections are turnedto form an acute angle, as shown in FIG. 1, the hinge strap 26 willoverlie opening 46, and the opening 44 in strap 26 will align therewithto permit entrance through both openings of pin 42. When thuspositioned, the pin 42 prevents angular movements, separation orclosing, of the sections 12 and 14 until the latch end 40 is lifted awayfrom the strap 26 to remove the pin 42 from the opening 46.

Sections 12 and 14 are each provided with a tubular locking member 50for locking said sections to sections 10 and 16 respectively. Section 12is provided with a similar, second locking member 50 for locking section12 to section 14 when the ladder is unfolded to form an extensionladder. Each locking member 50 is preferably formed of the samelightweight metal as the stile of the ladder and has a similarcross-sectional shape, but slightly smaller, so as to telescope withinthe stile from a fully inward position to a position protruding out ofthe stile and into the adjacent stile. This action is best illustratedin FIGS. 4 and 5, wherein FIG. 4 shows the locking member 50 fullyseated within section 12, whereas in FIG. the locking member has beenslid longitudinally to protrude into section 14 firmly securing thesections 12 and 14 together as if they were one piece. For movement andlocking of member 50, a stud 52 is provided, said stud having enlargedinner and outer ends 54 and 56 and being slideable in a transverse slot58 in member 50. The heads 54 and 56 form shoulders which retain thestud, or latching detent 52, assembled to member 50 and the stile 18. Alongitudinal slot 60 is formed in the stile 18 of the associated sectionto receive the stud 52 when it is positioned toward one end of the slot58. Thus the head 56 may be grasped in the fingers and pulled along slot60 to move member 50 longitudinally into the adjacent stile. Slot 60communicates at one end with a transverse slot 62 having opposedlongitudinal notches 64. Thus the stud 52 is movable longitudinallyalong slot 60, transversely into slot 62, and longitudinally into one ofthe notches 64, thereby locking the stud 52 with the connected lockmember 50 in its locking position protruding into the adjacent laddersection.

It will be noted that in certain positions of the ladder sections thelocking members 50 are retained in their locking positions by force ofgravity without the need for the transverse slots 62 and notches 62, 64.However, in other positions of the sections, as for example when thesections 14 and 16 are turned upwardly as in FIG. 3, the locking membersmust be moved upwardly into locking positions and the transverse slot62, therefor, is necessary to provide detents which will ensure that thesections will not become unlocked by gravity.

Assuming that the ladder is folded in compact form as shown in FIG. 8,for storage or transportation, and that it is desired to unfold thedevice to form an extension ladder, such as is shown in FIG. 3, it isthen only necessary to turn the sections with respect to each other inthe direction of arrow A, FIG. 4 until adjacent sections are aligned asin FIG. 5. The locking members 50 are then moved longitudinally bygrasping and moving the heads 56 of the detents 52 first along the slots60, and then transversely to move the detents 52 into the slots 62.Finally the detents are locked by another longitudinal movement into oneof the notches 64. When this has been done, adjacent sections are firmlylocked to one another, without danger of accidentally unlocking.

If a longer extension ladder is required, any additional number ofsections may be provided, as for example sections 66 and 68 similar tosections 10, 12, 14 and 16 and having hinge means 24 and a lockingelement 50, see FIG. 11. Desirably one of the extension sections, see66, may include a fixed locking tube 70 soldered, welded or otherwisefirmly secured within and protruding from the lower. end thereof. Theprotruding end of tube 70 may be pushed into the open, upper end ofsection 16 when the ladder of FIG. 3 is to be extended. If desired, thetubes 70 may be integrally formed as reduced portions of thecorresponding stiles of section 66.

Should it be desired to form a large step ladder, the folded device ofFIG. 8 may be unfolded so that sections 10 and 14 are respectivelylocked in alignment with sections 12 and 16, and sections 12 and 14 areat an angle to each other as shown in FIGS. 1 and 2. The sections 12 and14 are fixedly retained in this angle by the pin 42 on the latching bars36 falling into opening 46 of the section 14 as previously explained.The sides of the step ladder thus formed are thus firmly locked by theupper hinge assemblies 24 and are thus prevented from spreading underthe weight of the user.

Additional means are provided to assist in holding the sides of the stepladder at the desired angle. One such means includes a shelf 72 havingsupport arms 74 extended parallel to the shelf, each such support armbeing spaced to fit between a pair of stiles 18. Each arm 74 is providedwith an inverted, U-shaped spring clip 76 whose downwardly directed,open end spreads and contracts to admit and grasp the top of a lowerrung of section 12. Another spring clip 78, also of U-shape but openingupwardly, has one of its legs secured to the end of arm 74. Clip 78admits and clamps the same rung of section 14. It is apparent that, whenboth spring clips 76 and 78 of each arm 74 are thus engaged about therungs of the angled ladder sections, the shelf will be firmly secured tothe ladder and the ladder sections will be held from spreading orcontracting. When it is desired to fold the step ladder, the shelf 72,is merely lifted counterclockwise, as seen in FIG. 6, to release clips76 and 78 from the ladder rungs.

A somewhat similarly constructed top support is provided having thehorizontal upper platform 80 with two pairs of dependent legs 82 whichalso fit between the stiles of a section, as best seen in FIGS. 2 and 6.Each leg 82 is provided with an inverted U-shaped spring clip 84 securedat its bight to the bottom of the leg and adapted to resiliently clampthe upper rungs 20 of the ladder sections 12 and 14 between the stilesand the clips 76, 78. Referring to FIG. 6, the arrow C indicates thedirection in which the platform is moved to clamp the platform to thestep ladder. When it is desired to remove the top support for purposesof folding the step ladder, or to form an extension ladder, the platform80 is merely lifted in the opposite direction to spread the arms of thespring clips 84 and release the ladder rungs 20.

When it is desired to fold the step or extension ladder, this may beeasily done by grasping the heads 56 and moving the appropriate lockingstuds 52 from notches 64, through slots 62 and along slots 60 towithdraw the locking members 50 so that they no longer fit within astile of an adjacent section but are positioned completely within thestile of the next section.

The unlocked sections may then be turned about the pivots of the hinges24. However, if the adjacent sections are locked in their angularrelation, as for example sections 12, 14 in FIG. 1, these sections mustfirst be unlocked by lifting the ends 40 of the latch bars 36 to removethe pins 42 from the openings 46 in the stiles. The sections may then beturned and folded or unfolded, the pins 42 riding on the outer walls ofthe stiles as the hinges 24 turn with respect to the stiles pivotedthereto.

Should it be desired to form one, or two, small step ladders, the cotterpins 36 are removed from the upper hinges of the ladder illustrated inFIG. 1, and the hinge straps 26 are flexed to remove the studs 34 fromthe openings 30 in the straps. This enables complete separation ofsections and 12 from ladder sections 14 and 16. Each of the separatedparts of the ladder may then be formed into a small step ladder, asillustrated in FIG. 9. The hinges and latch pins 42 lock the section 10at the desired angle to section 12 and similarly section 14 to section16 in the manner as previously described with respect to sections 12 and14. The sections are desirably provided with additional anti-spreadingmeans in the form of pivoted bars 86 each having a hook end 88 andswingable to engage the hook ends over rungs 20 of an adjacent spreadsection. Once the two small step ladders have been formed and placed inspaced alignment, a platform 90 comprising a loose panel may be placedbetween the stiles and seated on the top rungs of both step ladders asillustrated in FIG. 9. It Will be obvious that the platform 90 may beprovided with the spring clips such as 76 and 84 to more firmly retainthe assembly together.

Although certain specific embodiments of the invention have been shownand described, it is obvious that many modifications thereof arepossible. The invention, therefore, is not to be restricted exceptinsofar as is necessitated by the prior art and by the spirit of theappended claims.

What is claimed is:

1. A combination folding step ladder and extension straight ladder,comprising a plurality of sections each having spaced longitudinalstiles connected by transverse rungs, the contiguous ends of the stilesof adjacent sec tions being curved to permit relative turning of thesections, hinge means located along the longitudinal center lines ofsaid stiles and continuously securing adjacent sections to each otherfor relative turning movements in either direction from a foldedcondition in which the sections lie contiguously in adjacent planes to afirst unfolded position in which the sections are in alignment to form astraight extension ladder and to a second unfolded position in which thesections are at an angle to form a step ladder, said hinge means havinglatch means cooperable with a stile of one of said adjacent sections tosecure said sections in said second unfolded position, and lock meansmounted on a stile of at least one section and movable longitudinally ofthe stile to engage an aligned stile of an adjacent section for securingthe sections in said first unfolded position.

2. A ladder according to claim 1 wherein said curved, contiguous ends ofthe stiles of adjacent sections are in abutting relation when theadjacent sections are in alignment.

3. A ladder according to claim 1 wherein said stiles are tubular andsaid lock means comprises a tubular member slideably housed within atubular stile of at least One section and movable longitudinally of thestile to protrude into an aligned stile of an adjacent section forsecuring the sections in said first unfolded position, and manuallymanipulative means for moving said lock means.

4. A ladder according to claim 3 wherein said manually manipulativemeans includes a lateral detent member projecting outwardly of theladder from the tubular member through its associated stile, said lockmeans housing stile having a longitudinal slot in a laterally outsidewall through which said detent member passes.

5. A ladder according to claim 4 wherein said tubular member is providedwith a transverse slot in which said detent member is slideable and saidlongitudinal slot of the stile is also provided with a communicatingtransverse slot for reception of said detent member.

6. A ladder according to claim 5 wherein said transverse slot of thestile is provided with longitudinal notches at one end to receive andlatch said detent member.

7. A ladder according to claim 1 wherein said hinge means comprisesstuds projecting from stiles of adjacent sections and a strap freelypivoted on said studs, said strap being readily removable from at leastone of said studs to enable separation of the associated pair ofsections, said associated pair of sections when separated being stillconnected to other sections and being unfoldable to provide separatestep ladders for support of a platform therebetween.

8. A ladder according to claim 7 wherein said latch means on the hingemeans for locking the sections in said second unfolded positioncomprising a resilient strip having a locking pin mounted on said hingestrap and detent means formed on one of the stiles to which the strap ispivoted, said locking pin being releasably engageable under resilientpressure of said strap with said detent means to lock the associatedsections together at a preselected angle.

9. A ladder according to claim 3- in combination with at least oneadditional section having tubular stiles connected by rungs to form anextension section, each tubular stile of said extension section having atubular projection of smaller cross section projecting from one endthereof for removable insertion into a tubular stile of the uppermostsection of said plurality of sections when unfolded and secured inalignment.

10. A combination folding step ladder and extension straight ladderadapted to be unfolded from a compact package to form either a selfsupporting step ladder or a straight extension ladder, comprising aplurality of sections of substantially identical size and dimension,each section having tubular stiles connected by fixed rungs, hinge meansconnecting adjacent sections for relative turning movements from afolded condition in which the sections lie contiguously in adjacentplanes to a first unfolded position in which the sections are inalignment and to a second unfolded position in which the sections forman angle, said hinge means including latch means for securing saidsections in said second unfolded position for use as a step ladder, lockmeans slideably housed within a tubular stile of at least one sectionand movable longitudinally of the stile to protrude into an alignedstile of an adjacent sectionfor securing the sections in said firstunfolded position, and manually manipulative means other than said rungsfor moving said lock means, said hinge means comprising studs projectingfrom stiles of adjacent sections and a strap freely pivoted on saidstuds, said latch means on the hinge means for locking sections in saidsecond unfolded position comprising a spring bar fastened at one end tosaid strap of the hinge means, said spring bar having a pin near theother end, an opening in said strap, a second opening in one of thestiles to which the strap is pivoted and so arranged as to align withthe first opening when the associated sections are unfolded to form astep ladder angle, and said pin of the spring bar being enterable intosaid aligned openings to lock the sections in said angle.

11. A combination folding step ladder and extension straight ladderadapted to be unfolded from a compact package to form either a selfsupporting step ladder or a straight extension ladder, comprising aplurality of sections of substantially identical size and dimension,each section having tubular stiles connected by fixed rungs, hinge meansconnecting adjacent sections for relative turning movements from afolded condition in which the sections lie contiguously in adjacentplanes to a first unfolded position in which the sections are inalignment and to a second unfolded position in which the sections forman angle, said hinge means including latch means for securing saidsections in said second unfolded position for use as a step ladder, lockmeans slideably housed within a tubular stile of at least one sectionand movable longitudinally of the stile to protrude into an alignedstile of an adjacent section for securing the sections in said firstunfolded position, and manually manipulative means other than said rungsfor moving said lock means, said hinge means comprising studs projectingfrom stiles 7 8 of adjacent sections and a strap freely pivoted on said445,453 1/91 Nowland 1822'7 studs, said latch means on the hinge meansfor locking 467,685 1/92 Hammon 182-l16 the sections in said secondunfolded position comprising 570,469 11/96 Furgason 182119 a resilientstrap having a locking pin mounted on said 2,183,251 12/39 Beggs 182163hinge strap and detent means formed on one of the stiles 5 2,963,76112/60 Haydock 297-153 to which the strap is pivoted, said locking pinbeing re- 3,078,953 2/63 Silen 182-163 leasably engageable underresilient pressure of said strap with said detent means to lock theassociated sections FOREIGN PATENTS together at a preselected angle.1,194,813 5/ 59 France- 10 343,539 11/21 Germany.

References Cited by the Examiner UNITED STATES PATENTS 96,495 11/69Smith 182-416 HARRISON R. MOSELEY, Primary Examiner.

REINALDO P. MACHADO, Examiner.

1. A COMBINATION FOLDING STEP LADDER AND EXTENSION STRAIGHT LADDER,COMPRISING A PLURALITY OF SECTIONS EACH HAVING SPACED LONGITUDINALSTILES CONNECTED BY TRANSVERSE RUNGS, THE CONTIGUOUS ENDS OF THE STILESOF ADJACENT SECTIONS BEING CURVED TO PERMIT RELATIVE TURNING OF THESECTIONS, HINGE MEANS LOCATED ALONG THE LONGITUDINAL CENTER LINES OFSAID STILES AND CONTINUOUSLY SECURING ADJACENT SECTIONS TO EACH OTHERFOR RELATIVE TURNING MOVEMENTS IN EITHER DIRECTION FROM A FOLDEDCONDITION IN WHICH THE SECTIONS LIE CONTINGUOUSLY IN ADJACENT PLANES TOA FIRST UNFOLDED POSITION IN WHICH THE SECTIONS ARE IN ALIGNMENT TO FORMA STRAIGHT EXTENSION LADDER AND TO A SECOND UNFOLDED POSITION IN WHICHTHE SECTIONS ARE AT AN ANGLE TO FORM A STEP LADDER, SAID HINGE MEANSHAVING LATCH MEANS COOPERABLE WITH A STILE OF ONE OF SAID ADJACENTSECTIONS TO SECURE SAID SECTIONS IN SAID SECOND UNFOLDED POSITION, ANDLOCK MEANS MOUNTED ON A STILE OF AT LEAST ONE SECTION AND MOVABLELONGITUDINALLY OF THE STILE TO ENGAGE AN ALIGNED STILE OF AN ADJACENTSECTION FOR SECURING THE SECTIONS IN SAID FIRST UNFOLDED POSITION.